“A/C OFF” after radiator replacement
Thread Starter
Senior Member
Joined: Oct 2011
Posts: 399
Likes: 14
From: Chicago, Illinois
2008 S63
“A/C OFF” after radiator replacement
Had my radiator replaced recently and noticed the mechanic did not recharge the air conditioning system. Well I noticed the ac will not turn on and stays in off mode even after recharging the ac myself. The system is properly charged but I still get the check next to the ac off. Anyway to reset and resolve?
Senior Member
Joined: Jul 2011
Posts: 328
Likes: 56
2012 S350 Bluetec 4MATIC; 2011 ML350; 2005 C230k;
AC system has pressure sensor and it will not turn on if the pressure is low. Did you vacuum the system before you recharge it? There is no way the system is properly charged if the compressor is not turning on. You actually need to have compressor running to charge the system.
If you click on the AC on command you will have additional menu where you can turn on the AC.
See attached manual
If you click on the AC on command you will have additional menu where you can turn on the AC.
See attached manual
Thread Starter
Senior Member
Joined: Oct 2011
Posts: 399
Likes: 14
From: Chicago, Illinois
2008 S63
Yes ac was evacuated with no leaks. But ac will not switch on no matter what. It stays in the off position. Essentially we attempted to fill the system with a small amount to “wake up “ the system in order to cycle the ac on but still nothing.
Super Member
Joined: Jun 2003
Posts: 713
Likes: 147
From: Aridzona
'15 S550, '10 E350 P1/P2, '02 ML320
There is a condition where if the refrigerant pressure drops too low the compressor will need to be reactivated via the SDS, this to protect the compressor and system components. I replaced my compressor last year, fully recovered the refrigerant and recharged the system and did not have to reset it via SDS. However I did not operate the A/C with the refrigerant low, I was replacing the compressor due to it making the 'I'll die soon, just you watch' noise.
Just re-read your OP, I wonder why replacing the radiator would cause the HVAC system to depressurize?! I replaced mine and did not need to do so.
Just re-read your OP, I wonder why replacing the radiator would cause the HVAC system to depressurize?! I replaced mine and did not need to do so.
